Page 231 - Foton Workshop Manual - Auman EST-M

Diagnosis - Diagnosis-fault diagnosis of electronic and electrical parts DI - 177

Failure phenomenon Phenomenon description IN

Internal and external circulation Ignition switch is in "ON" gear, press the internal and external circulation mode cannot
DI
motor not working be switched when pressing the selection button of internal and external circulation.

Diagnosis procedure
EG
1. Check the internal and external circulation motor

a. Ignition switch:LOCK.
TR
b. Disconnect internal and external circulation motor connector B055.

c. Connect the positive terminal of 24V power supply to No. 3 terminal of B055 and the negative terminal of
AX
24V power supply to No. 5 terminal to observe whether it is working properly. Connect No. 3 terminal to

the negative terminal of 24V power supply and No.5 terminal to the positive terminal of 24V power supply,
and check if the direction of rotation changes. FR
Check if the result is ok?

Yes>go to Step 2. ST
No> Replace internal and external circulation motor.
2. Check internal and external circulation motor to A / C switch A harness and connector. BR

a. Ignition switch:LOCK.
BW
b. Disconnect A/C switch A connector B037.

c. Disconnect internal and external circulation motor connector B055.
EL
d. Take a multimeter to measure the resistance between No.

3 terminal of B037 and No. 3 terminal of B055as well as the
resistance between No. 9 terminal of B037 and No. 5
terminal of B055.
Standard resistance:

Multimeter connecting terminal Standard value

B037(3)-B055(3) About 0Ω

B037(9)-B055(5) About 0Ω

Check if the result is ok?

Yes>go to Step 3.

NO>repair or replace the open harness.
3. Replace the AC controller

a. Replace with the same specification of AC controller and recheck.
Is the test result ok?
Yes>replace the AC controller.

NO>retest the above steps.

DI-177